The transformation of the electricity market is in full swing: Large amounts of renewable, decentralized energy sources are being developed and consumers are becoming more and more prosumers, who «optimize» themselves. This brings new challenges to the transmission system operators (TSO), which are responsible for avoiding overloads in the network, keeping the voltage within the permitted range and ensuring the balance between feed-in and feed-out at all times. Could a better coordination with distribution system operators (DSO) help to face these challenges? And what should this coordination look like? These questions will be discussed on October 3, 2019 at the public workshop from the International Smart Grid Action Network (ISGAN) in Montreux.